These are the thing you need to learn, in order of how you need to learn them.

1) Learn English

Difficulty – Medium

If you want to sell your stuff on the global market then you must know English.

You need to know it in order to understand all the tutorials and books about web development that you will be learning from.

Later on, when you start selling your themes and templates you need to write documentation and offer support, which can not be done without good knowledge of the English language.

2) HTML & CSS

Difficulty – Easy

These are the first two coding languages you need to learn. Those two are fundamental, but they’re also the easiest.

3) JavaScript & jQuery

Difficulty – Medium

You need to learn the basics of JavaScript, no need to go deeper but would definitely be a plus. jQuery is a JavaScript library that makes numerous JavaScript tasks easier to handle. It’s also what powers all those sliders and animations in 100% of the themes.

4) PHP

Difficulty – Hard

PHP is where things get harder. It is not needed if you will be making HTML templates, only if you’re going to be building WordPress themes (I’m talking about Themeforest here, but you’ll need PHP for a lot of things outside of WordPress themes).

5) WordPress themes & plugins

Difficulty – Medium

WordPress themes and plugins development is a mix of all those mentioned above. But when you’re experienced with all of those, WordPress development won’t be hard at all.

Summary

Depending on how fast you learn you will need 3 to 5 years to learn all that and have enough experience to build HTML templates and WordPress themes that you can then sell.

themebros said
By the way, if you didn’t have the time to check it all out yet, the pen is a USB memory stick.
Got a red Moleskine, still haven’t written anything in there, want to improve my handwriting first.

The USB is 2GB and veeeryyy slow

Haven’t had a chance to use it much, broke it a day later, it didn’t fit in the TV (since it’s quite “fat”), so tried to slim it up a bit with a knife, didn’t work out.

Two Tim-Tams?!? I got only one, if I knew there would be two just half a year later I would have slowed down with the themes. That thing is epic, my mouth is watering right now. Just got motivated to make this account Elite as well

The Vegemite… You can put 2 kilos of Nutella on top of it and it would still be gross

By the way, if you didn’t have the time to check it all out yet, the pen is a USB memory stick.

Got a red Moleskine, still haven’t written anything in there, want to improve my handwriting first.